


Kinktober 2020 - Day 16: Fucking Machine (Alphyne, NSFW)

by yastaghr



Series: Yastaghr's Kinktober 2020 [16]
Category: Undertale (Video Game)
Genre: Alphys/Undyne-centric (Undertale), Bad BDSM Etiquette, Dildos, Established Alphys/Undyne (Undertale), F/F, Fucking Machines, Kinktober, Kinktober 2020, Overstimulation, Smut
Language: English
Status: Completed
Published: 2020-10-16
Updated: 2020-10-16
Packaged: 2021-03-09 02:35:33
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 569
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27047335
Author URL: https://archiveofourown.org/users/yastaghr/pseuds/yastaghr
Summary: ((Warning: Bad BDSM Etiquette))Alphys has built and tested a sex machine for Undyne!
Relationships: Alphys/Undyne (Undertale)
Series: Yastaghr's Kinktober 2020 [16]
Series URL: https://archiveofourown.org/series/1947772
Comments: 2
Kudos: 19





	Kinktober 2020 - Day 16: Fucking Machine (Alphyne, NSFW)

**Author's Note:**

> Broke/dislocated my toe :( No idea how. Started a new psych med. Hopefully it'll fix a few things. Hiatus ends 31 Oct

Dr. Alphys caressed Undyne’s face. Her face was covered in sweat, glistening in the low light of this room. Her whole body was like that, sweating and gleaming in the light. The only part of her that wasn’t shiny because of the sweat was the area between her legs. That was glistening with lube and slick from her pussy. 

Undyne was currently spread out on their bed, her four limbs tied to different corners of the bed and stretched to their max. She had a huge red ball gag in her mouth. Situated between her legs in the bed was a machine. It looked, on the outside, like a big black barrel with a mounting point on a stick poking out of the end nearest to Undyne. Attached to that mounting point was a purple dildo. It was a straight one, but there were veins popping on the sides of it and it tapered to a wider base than at the tip. The whole barrel was connected to the wall by a plug.

Alphys carefully moved Undyne’s bangs out of her eye and slid a finger down her neck to her shoulder. “N-n-now, you asked me to, um, build a machine to fuck you hard? I th-th-think I might have made one. I, um, tested it out on myself, of course, but… the results were inconclusive? So I th-th-thought… why not test it out as a final product? So, here we are! Are you r-r-ready?”

Undyne narrowed her one eye as if to say, “Are you kidding me?” Then she nodded like crazy, finishing the hypothetical statement with, “Of course I do! Turn this damn thing on already!”

How could Alphys argue with consent like that? She turned to the remote in her hand and pressed the buttons to turn the machine onto it’s first level. The little rod with the dildo slowly extended and pushed it into Undyne’s cunt. It went in smoothly, partially because of all of the slick and lube, but also because this was Undyne’s favorite dildo. She narrowed her one eye.

“T-t-too slow?” Alphys asked. Undyne nodded, and she said empathetically, “I know, it was too, um, slow for me, too. So I added, um… 27 more levels? Let’s try level 13.”

Alphys pressed a few buttons, and soon the dildo was pumping in and out of Undyne’s pussy at decent pace. Undyne tried to arch her back and moan. She only succeeded at one out of two. The ties Alphys had placed her in weren’t exactly very forgiving. The moan was music to her mate’s ears, though.

Alphys bent down beside her and whispered in her ear, “Good? This was, um, my favorite level. But… it wouldn’t really be fair to you not to l-l-let you experience  _ all _ the levels, would it?”

With that, Alphys hit a button on the remote that she hadn’t touched yet. It was marked, “The Randominator!” Once it hit, you could hear Undyne scream around the gag. This button would cycle her through every level the machine was capable of at random intervals until she had completed a random number of orgasms that was somewhere between 3 and 10. Or, of course, until she fainted. Alphys wasn’t that cruel.

She was, however, just cruel enough to say, “Well, look at the time! I’ve g-g-got an experiment to get back to! I’ll, um… be back for you tonight? Bye!”

**Author's Note:**

> You can find me on:
> 
> Pillowfort - https://www.pillowfort.social/Yastaghr  
> Tumblr - https://yastaghr.tumblr.com  
> Twitter - https://twitter.com/yastaghr * Most active


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